Idrift4wd.....would a misfire code be considered an injector failure?
Or injector failure has their own code?

Cobbs recommendation falls under the tolerances for the Bosche plugs, so either will work since they recommend 20 plus or minus 3 which puts you at 17 or 23. I did mine at 17 and have no problems (also used bosch plugs)

as for the misfire, it could be caused by a faulty injector but most times it is either plugs or coil. I would say replace the plugs and clear your codes, test drive and see if you get the issue again. If you do get a misfire then you can start the troubleshooting process of changing the coils around. If the misfire follows the coil then the coil is bad if the misfire stays in the same cylinder it may be the injector.

Learn to use either realoem.com or bmwfans to check compatability.
If you use 30 ft pounds torque good luck.
BMW recently changed their spec from 17 ft pounds to 20 because of plugs backing out.
Whether you use anti-seize or not is up to you. The bright shinney plug threads are the ones that don't require anti-seize. However I use copper anti-seize regardless just in case having had a plug seize in a aluminum cylinder head.